Lab Versus House Mouse

Some behavioral traits, like female aggression, were lost with domestication, a study shows.

By Jef Akst | August 21, 2014

WIKIMEDIA, RAMAWhile the laboratory mouse has proven an invaluable model of physiology and disease, years of inbreeding have changed the animal from its wild ancestors. The lab mouse is “larger, fatter, calmer, and less aggressive” than its wild counterpart, Science News reported, and it lacks some of the behavioral traits that characterized its ancestors, according to a study published in Nature Communications this month (August 5).

“Lab mice are easy to work with and breed, relatively cheap and there are powerful genetic models, behavioral paradigms and sequenced genomes at our disposal,” Stephen Liberles, a cell biologist at Harvard University who was not involved in the study, told Science News. “[But this study] highlights the importance of considering the natural diversity of wild animal populations.”

Lead author Lea Chalfin of the Weizmann Institute of Science in Israel and colleagues explored the behavioral differences between lab and wild mice by breeding the two for 10 generations. The study allowed the researchers to identify specific behaviors that have been lost from today’s lab strains, in particular, female aggression. While female wild mice will lash out against pups that are not her own, female lab mice are often seen adopting and nursing stray pups. The team even pinpointed an underlying genetic component that effected the behavioral change: TrpC2, involved in pheromone communication between wild mice, appeared nonfunctional in the lab variety.

“Lab mice can serve us a lot and answer many questions in medicine,” study coauthor Tali Kimchi, a Weizmann neurobiologist, told Science News. “But for some questions, like aggression in females, they may not be the best model.”